Multiple-arc lamp



April 20 1926;

E. F. WINFIELD ET AL MULTIPLE ARC LAMP Filed August 18, 1919 I 3 Sheets-Sheet 1 3? p i2 /nymfors W M M M flffo-ffemer i lid by A ril 20 1926'.

. 1,581,560 E. F. WINFIELD ET AL I MULTIPLE ARC LAMP Filed August 1919 3 Sheets-Sheet 2 A ril 20,1926. 7 1,581,560

' E. F. WINFIE LD El AL MULTIPLE AjRC LAMP I Filed August 18, 1919 s s eds-sheet 5 I Patented Apr. it, i925.

.. r on u and may EDWARD F. 'WINFIELD AND GTTO KERNEB; 01? LOS ANGELES, CALIFORNIA.

MULTIPLE-ARC LAIiIP.

Application filed August 18, 1919.

To (.11 1 7 710222 2'2- JiY/Lf/ concern:

l e it known that we, EDWARD F. IN- ru-mn and O'r'ro Knnnuu, citizens of the l nited. Eitates. residing at Los AHQGlGS. in the con or Los 'tugeles. State of California, have "iOlIl Cljl' invented new and useful lmpronxements in Multiple-Arc Lamps, of which the followi is a specification.

This invention relates to are lamps; and, without being limited thereto, relates more specifically to such are lamps as are particularly adapted for motion picture and other photographic work.

In such lamps it is desirable to maintain arcs as nearly uniform as possible and to have the least possible fluctuation upon the periodic striking of the are. It is an" oloiectof this invention to accomplish these desirable qualities; and, furthermore, to accomplish them in a multiple arc mechanism. And, generally. it is an object of the invention to provide an etlicient multiple arc lamp, simple and effective in structure and operation, in which there is uniformity of OQQZ'lfiOll and a minimum of fluctuation of the several arcs. We illustrate a lamp having two arcs; but our structures and our modes of operation may be applied to a single are or to more than two arcs. The present invention provides an arc lamp which. is particularly adapted for motion picture photography. It provides an even steady light, which is necessary for successful taking of motion pictures. This makes he invention of great commercial value and superior to ordinary arc lamps for this particular class of work, as it minimizes the cost of retaking; pictures. A great saving is effected by the invention in this class of work as it eliminates a waste of valuable film which is very large when an ordinary are lamp is used.

The details of construction and operation of a preferred form of lamp embodying the invention will be understood for the following descrip ion, reference for this pur-- pose heme had to the accompan ine'fdraw-- C7 C inn. in which.

Fig. l is a front elevation ofthe preferred form of mechanism; Fig. 2 is'a section taken as indicated by line 22 on Fig. 1; Fig.- 3 1s a side elevation; Fig. 4 1s a plan: v1ew;

Fig. 5 is aneularged detailed section taken:

Serial No. 313,117.

as indi 'ated bv line on Fig. 3; Fig. 6 is an enlarged detailed section taken asindicated by line 6-6 on Fig. l; and 7 is a plan section taken on line 77 of Fig. 3.

In a preferred form of the invention we preferably use two arcs. The lower carbons 1O of'thcse' arcs are supported and held in suitable supporting brackets 11 and clamps 12. The upper carhons 13 extend through clutch mechanismsl l. The clutch mechanism 14.- for each of the: upper carbons l3 embodies a vertically movable clutch plate 15 having an aperture 16 through which the carbon passes. At its forward end this clutch plate 15 is pressed downward by a spring 17 coiled around a guide rod or post 18, which passes through an aperture 19 in the forward part of the clutch plate. The post 18 extends; between bracket 20, which is mounted on a frame 21, and a guide plate 22. The guide plate 22 is mounted on posts 23. A stop screw 24: extends downwardly from the guide plate 22 and is screw-threadedly engaged in said plate. The guide plate 22 is split where the stop screw 24 passes through it and set screw 25 is provided to clamp the screw 24 in place. The stop screw 24 forms a stop for the clutch plate 15 and limits its upward movement. The carbon 13 moves and is guided vertically through aperture 26 in guide plate 22 and aperture 2? in bracket 20.

The arrangement and organization of the parts is such that when the rear of the clutch plate is moved upwardly to a somewhat angular position, the carbon is bound in the aperture 16; and when the carbon is so bound, then the carbon and the clutch plate will move upwardly together against the downward pressure of spring 17. henever the clutch plate moves down to the position shown in the drawings, that is, when the current is turned off, it seats fiat ly upon the bracket- 20. Then the carbon 13 will be released and may fall immediately upon the lower carbon 10. It will be noted that the forward or outer part 15 of the clutch plate is turned up diagonally, so that the downward pressure of spring 17 tends to prevent the forward part of the clutch plate from lifting too high, and keeps the plate tipped wheuthe' back edge all is inised. The action of the spring is to assist the clutch plate to tip bcf re it begins its bodily upward movement and thereby cl tch the carbon at the inception of its upward n'lovement.

The rear end of each clutch plate is connected to a lever arm by links 31. The linrzs are normally loose when the mechanism at rest or when the clutch plates are seated and the carbons are being dropped. The arm 30 is pivotally mounted at 232 on a bracl iet 32 and has extending through it a set screw 33 which an insulating;' sleeve carried on a transverse rod 85. The insulating sleeve 3% is mounted on one end of a lever 36 which is pivotally mounted also at 32 on bracket arm 30 being forked shown in Fig. l, to allow this construction. In the other end of arm 36 there is an insulating sleeve 37 in which is carried a rear cross rod 38. A motion steadying device, )refeiably in the form of a small dash-pot mechanism 89, is connected at 40 to each lever This mechanism comprises the simple arrangement of a small cylinder ll having therein a piston 42 lit ting the cylinder more or less tightly, the piston being mounted upon a rod .3 which is connected at 40 to the lever The cylinder a l has an upward extension l t pivotally connected at 415 to the upper end of a suitable bracket 16; and extension 4% can ries a valve 46 which may be arranged to check inward movement of air into the cylinder. The leakage of air around piston -2 allows slow downward movement of the piston in its cylinder; the upward move ment is relatively free.

We have now described in detail the immediate operating mechanism for each. carbon; and there will be as many of such mechenisms there carbons in the mul tiple lamp. ln the present are there are only two, but it will be readily understood by those skilled in the art how the parts of the meclnmism now about to be described may be adapted to different numbers of carbo-n operating mechanisms. And it may be well to point out here that it is not necessary to have an individual dash pot for each carbon mechanism.

The forward cross-rod and rear crossrod 238 connect the arc lamp mechanisms. lion extends through the sleeve of each mechanism and cross-rod 38 extends through sleeve of each mecnanisn'i. On the ends of l'OSS-lOCl 35 are rigidly mounted arms 50. One end of each of the arms 30 is rigidly connected to cross-rod 38 while on the other ends of the arms are adjustable counterbalance weights 51. The counterbalance weights being, adjustable, may be set or reggalated to suit the voltage and friction of the mechanism. Mounted on the heel: side at the lower on d of frame 21, is a solenoid 52 pro vided with a core adapted to be drawn downwardly into the solenoid. Core is connected, through the medium of a spring 54: and arm 55 to cross-rod 38. In order to prevent the core 53 from being accidentally removed from the solenoid a heavy wire or small rod 56 (preferably non-magnetic) extends from the lower end of the C016 through the solenoid. The lower end of wire 56 is bent shown in Fig. 3 so as to prevent the core from accidentally passing out of the solenoid.

The counter weights 51 tend to keep the entire mechanism in the position as shown in the crawings. If so desired springs may be substituted for weights 51. The loose linl; connections at 31 allow the clutch plates always to rest flatly on brackets 20 so the when the pull of solenoid 52 is released, the spring 54- and dash pots 89 damp elf vibrations in the carbon operation mechan is which would otherwise be excessively caused by vibrations of core It is to be noted that the arms 50 and the cross-rods and '38 form a rigid frame and that arms 36 move rigidly with that frame. All these parts, and also arms 30, oscillate about the axis 32 as a center. By adjustn'ient of screws 33 the loosenoss of links 31 may be adjusted in equality, so that, when the solenoid acts to tilt the oscillating members and lift the looselinks, the several carbons will begin to rise at the same time and will be lifted equal distances. The several arcs are connected in series and the solenoid 52 is also connected in the same series circuit. The two supply wires 60 and 61 lead to binding posts and 63, respectively. A wire G-l leads from a binding post (32 to the lower carbon 10 of one of the arcs. From the up per carbon of this are a wire leads to the lower carbon of the other are. From the upper carbon of the second are a wire leads to solenoid 52 and a wire 67 leads out of the solenoid to binding post 63 and thus to the other supply wire (it. In each case the wires 65 and 66 are divided into two parts which are connected together by connecting with binding clamps 70. T he upper parts of these wires, being the parts that connect directly to the upper movable carbons 1.3, are preferably flexible so as to allow the proper movements of the car bons.

When the mechanism is at rest and there is no current flowing, the parts are in the position shown in the drawings. As soon as current is supplied, the carbons being in contact, the solenoid is energized and draws core 53 downwardly. Spring 54. and the inertiaof the parts (and the weights 51 play a part during the first movement of taking up the looseness in the links 31) serve to take up any sudden shock, and dash-pots 39 also serve to retard the movement of levers 36. The clutch mechanism is gradually moved upwardly, the rear ends of clutch plates 15 first moving upwardly, tipping the clutch plates in the manner h-ereinbefore described and causing the clutch plates to immediately bind the carbons. Further upward n'iovoment of the clutch plates then lifts the carbons and separates the upper carbons from the lower carbons, forming arcs which are gradually lengthened until the clutch plates strike stop screws 24. The stop screws 24 are set so that the arcs are not initially pulled out to their maximum length. The burning away of the carbons causes the arcs to lengthen, and to increase the resistance in the circuit and to thereby decrease the pulling powerof the solenoid. As the arcs gradually lengthen, the solenoid core 58 moves upwardly, lowering the clutch plates 15 as the carbons burn away. A fair balance is struck between the forces tending to lower the carbons and the solenoid force tending to raise them, so that the arcs are kept at a substantially constant length. However, as the core 53 moves upwardly it moves to a position where, for a given amount of current in the solenoid, it is attracted downwardly with a greater force; and the result of this is that as time goes on, the lengths of the arcs are somewhat increased. This action is caused by the relation of the core to the solenoid, its lower end moving from a position below the center of the solenoid to a position when it is entirely above said center or in about the same relation to the solenoid as shown in the drawings; and the solenoid not having a magnetic end plug. The clutch plates are gradually lowered until they strike the brackets 20, releasing the carbons and allowing them to drop slightly and enough to decrease the resistance in the circuit when the solenoid immediately lifts the clutch plates and carbons. The arcs are thus kept substantially uniform without the necessity of frequent restriking. There is some fluctuation in the arc resistance and the core 53 vibrates to some extent at all times. The spring 54: and the dash pot 39 take up most of this vibration; in fact, due to the action of the spring and the link connection and the inertia of the various parts of the mechanism particularly the weights 51, practically none of this vibration reaches the carbons themselves. If for any reason one are is broken, the current then ceases to flow and the parts all instantly drop to the position shown in the drawings, and both upper carbons drop on the lower carbons. The current is again established and the mechanism immediately clutches the carbons and raises them to form new arcs. Such restriking of the arcs evens up the lengths thereof in event that one of them has become too long due to uneven dropping of carbons through the clutch plates in the normal operation, which uneven feeding causes breaking of the longer arc and therefore restriking of both. The operation of dropping the carbons and breaking them up and forming new arcs is almost instantaneous.

The dash pots 39 retard and steady the movements which raise the upper carbons. It will be noted that although these dash pots are independent and the clutch mechanisms, etc, are also independent of each other, the mechanical construction and actuation is such that both of the carbons are dropped simultaneously. This simultaueous dropping of the carbons causes the r equalization of any difference in lengths of the arcs if the carbons are dropped.

' The dash pots 39 also have, in combination with the spring 5e, a direct efie'ct in the operation which causes the final breaking of the arc and resetting of the carbons. It is to be noted that the dash pots resist only upward movement of the carbon. Thus, although the carbons may move downwardly and shorten the arcs, in vibrations or fluctuations caused by'vibratory movement of core 53, yet the upward movement of the carbon is relatively slow; the tendency being to expand spring 54 rather than move the carbons quickly upwardly. The result of course is that the major portion of the vibrations is taken up in the spring 54, without any excessive vibratory movement of the carbons, either up or down. The are is thus steadied and held constant; and at the same time the gradual downward movementof the clutches and of the carbons, as the carbons burn away, is not opposed.

The above description has been that of the lamp mechanism separate from any covering or casing. It will be readily understood however, that the mechanism can be readily installed or mounted in various forms of casings and that the invention is entirely independent of any casing or housing in which the lamp may be installed.

'We have now explained, in its preferred form, an arc lamp embodying our invention; and certain features of our invention will be understood to be included in the mechanical arrangement and organization of parts to efliciently accomplish the ends herein set forth. But the primary feature of the invention is the provision of an efiicient form of single or multiple arc lamp, and particularly a multiple arc lamp, with mechanism for its eflicient operation, gradual feeding and for giving a steady unvarying light.

Regarding our invention as being broad in its scope we do not limit ourselves to the specific details herein set forth, but reserve whatever changes or modifications that may suggest themselves to those skilled in the art or fall within the scope of the following claim,

Having described a preferred form of our invention, we claim:

In an arc lamp mechanism, a frame with means for carrying a stationary carbon and a guide for a movable carbon, a clutch plate adapted when lifted to engage and lift the movable carbon and when lowered to release the movable carbon, an oscillating frame mounted on the first mentioned frame, an adjustable Weight carried by the oscillating frame at one side of its pivot, a solenoid spring connective means between the solenoid and the frame, a motion retarding means connected to the frame to retard upward movement of the weighted side of the frame and to allow free downward movement thereof, an arm connected to and oscillating with the oscillating frame and having an end projecting past the oscillating center on the weighted side of the frame, a free arm pivoted on the oscillation center of the frame, adjustable means on said free arm resting on" the end of the oscillating arm so that the position of the free arm may be adjusted with reference to the oscillating arm and frame and so that upward movement of the weighted side of the frame raises the free arm and downward movement of that side of the frame leaves said arm free to fall, and a loose link connection between the free arm and the carbon clutch.

In witness that we claim the foregoing we have hereunto subscribed our names this 11 day of Aug. 1919.

EDWARD F. VVINFIELD. OTTO KERNER. 

